Waeco Cooler Circuit Board Problems?

harvvectra2012 · Member

Waeco Cooler Circuit Board Problems?

DeBe · Guru

WAECO CD-40 AC VERA.JPG WAECO CD-40 AC VERA 2.JPG WAECO CD-40 AC VERA 8.JPG Hi Chris & Marily. Can you post a sharper picture of the otherside of the board? Most probable cause could be dry solder joints on the Relay or the 2 Regulators 7810 & 7805. There should be 12 or 24VDC on one side of the 7810 reg & the center lead is ground, the other lead should have 10V DC. The 7805 reg should be the same but have 5V DC on the other leg.

harvvectra2012 · Member

Thanks for the fast reply! We're on the road at the moment, but when we land somewhere long enough for me to get the board back out I will take a picture of it and post for you to take a look. I looked at it for the obvious; no burnt markings or obvious broken solder joints. There was a dark area, but I attributed that to the "shelac" they coat the bottom of the board with.
Hopefully, I'll have a chance to do that with in the next two days.

Thanks Again :)

Chris

DeBe · Guru

Waeco CF-40.jpg Hi Chris. Hope you can read the picture ok as ive marked what should be on the Reg pins & where. They are a fairly common 3 terminal Voltage reg worth about $1.50 each. The LM7810 should read 10V & the LM7805 should read 5V. Do the tests using the fridge on 12v. Is the discolouration around the 7810 reg carbon or heated glue on the board? Surely there is a Waeco office in America that boards are avalable from? With no controls working id suspect the 5V reg as the 10V reg mainly suplies the cooling fan & internal light in the fridge, if there is a lamp.

-- Edited by DeBe on Tuesday 14th of August 2012 01:35:45 PM

-- Edited by DeBe on Tuesday 14th of August 2012 09:42:38 PM

harvvectra2012 · Member

Hey DB,

I apologize for taking so long but, we just got still long enough for me to take it back out and take some pictures.
.

I have attached the pictures...the back has a discolored portion right behind where the power leads come in, but though the picture doesn't show it well, there really doesn't llok to be a break in the circuit. I've also attached a picture of the power supply, but again, I am reading 26 volts to the board.

I will really appreciate any help you can ontinue to be; even it's just telling me where to find a new board.

Thanks again!

Chris

LeighW · Member

The discoloration appears to be associated with what might be a voltage regulator.

If the board is black it is probably been carbonised by heat, if the voltage regulator chip has
gotten hot enough to char the board it may also have failed due to heat. If you decide to replace
the regulator be aware that carbon tracking may occur on the burnt board.

Cheers
LeighW

oldtrack123 · Guru

Hi Chris

The voltage reg seems to have a substantial heat sink

Looking at from that side it does not appear to show signs of heat,even in close proximity to the actual cooling fin

Is the discolouration on the back due to heat??

I would suggest you reconnect & do the voltage checks as indicated by De Be

Just replacing the reg may still leave the cause

Also check how hot the heat sink gets

It should be touchable

Just replacing the Voltage reg may still leave the problem even though they are quite cheap & easy to replace

It needs further investigating IMHO,

De Be is the expert on most Waeco electrics !!

Peter

harvvectra2012 · Member

Thank you DB & Peter! You guys are a wealth of knowledge and I will follow your diagnostic advice. I'm currnetly in central Montana, USA and plan to be going to north to Glacier National Park so I doubt I'll find somewhere to buy the 5 volt reg. Hopefully, I won't be in need of the cooler up there ;)....however being an A/C / Electrical contractor, I hate to be bested by a device :).

I have done several searches for WAECO / Dometic and found some sites, but have yet to hear back from the thier customer support.

Thanks again for all your prompt help! I will let you know how it works out and where I find the parts...it might help someone else on my side of the pond.

Safe travels and thanks so much again!

Chris

03_troopy · Guru

Chris, the 7805 reg is a common garden variety component used in lots of electronic devices. You should be able to pick one up in any electronic hobby store, possibly Radio shack or similar. Failing that, any consumer electronic repairman would have a few lying around his workshop and should be able to sell you one for a couple of dollars. But as has been already said, you need to find out what was drawing excessive current through the regulator to cause it to overheat.

harvvectra2012 · Member

Thanks to all for the wonderful help! I managed to find the circuit board. I figured it's a little more $, but easier than trying to soulder in a reguator on a picnic table LOL!

I contacted customersupportcenter@dometicusa.com and they put me in touch with an authorized dealer and sent me the part break-down of this cooler. I can't seem to attach a .pdf file and don't have the program to convert it now, but will be glad to email to who ever may need it.

Hopefully, anyone else searching for this problem will have a shorter learning curve.

Cheers from our side of the pond!

Chris